[ARC5] Army/Navy transmitters from a NON COLLECTOR viewpoint, the ham version...

Sun Feb 9 17:19:41 EST 2020

 If the other transmitter is an ARC-5, the connector is as hard to find as the rack itself.  Fair Radio has some replacement "pulls" from SCR-274 types, but no ARC-5 type. 
Besides, the ARC-5 plug diameter is at least 1/4 to 5/16 inch more than the scr274.
I would suggest that you go with the mini banana plug idea. If you want to be extra fancy, you could mount them on a piece of plexiglass. 

    On Sunday, February 9, 2020, 5:06:19 PM EST, Peter Bertini <radioconnection at gmail.com> wrote:  

 The rack is in  poor condition...  I was going to replace one of the chassis mount maleswith one that will properly mate my other transmitters. My problem is finding a connector, or having  to make one with the miniature banana plugs I have.on hand.  I don't want t modify the rack, but having the "wrong" transmitter in one bay isn't going to bother me.  what is the part number for thechassis mount fitting that I need?
On Sun, Feb 9, 2020 at 4:57 PM Mike Everette <radiocompass at yahoo.com> wrote:

 The reason the FT-226 rack does not work with the ARC-5 series is the transmitter power plug.  If you compare one of the BC-series or ATA series transmitters (either of which will fit the FT-226 rack) to one of the ARC-5s, you'll see that the power plug for the ARC-5 is slightly larger and with different pin spacing.  It won't mate with the plug in the rack you want to use.
Consequently, the power plugs in the ARC-5 series racks don't mate with the BC or ATA transmitters.
This was done originally to avoid confusion between the series by elinating the possibility of plugging the wrong transmitter into a rack.  In the case of the ARC-5 transmitters, the wider pin spacing very likely has to do with higher peak voltages resulting from plate modulation.  At ground level it probably isn't anything to worry about, but as altitude increases, the breakdown voltage decreases.  In unpressurized WW2 aircraft this was a real concern.
In my opinion, and I'm sure that of many others on this group, learning the details and the ins-and-outs of these various systems is part of the fun.... But of course the real fun is getting these radios on the air.  I think you are on the right track with this.
Beware!  This all can lead to a disease called "ARC-5 Fever."  Who knows where you'll wind up.  One day you just might want to put together a complete system.  Or not.  Just have fun with it.
A hint on getting the radios on the air:  You can use miniature male banana plugs to mate with the original power connectors.  There was an article in QST Magazine about 5 years or so ago about the transmitters which pointed this out.  No need to change the socket to an octal plug as was common in the 50s and 60s.
73
MikeWA4DLF

    On Sunday, February 9, 2020, 12:55:40 PM EST, Peter Bertini <radioconnection at gmail.com> wrote:  

 I'm probably in the wrong group... but...
Beyond the bewildering confusion deciphering between ARA/ATA, CBY/CCT, SCR-274, BC-xxx, T-xx/ARC-5 variants... I am looking for a common denominator..
Assuming one  is NOT interested in the correct accessories, cables, modulators, dynamotors, etc...
And for the sole purpose of putting any variant on the air with minimal modifications to transmitter itself... don't wantshelf queens, I want these to be usable and on the air.  
1: Can either variant be either screen or plate modulated? I don't see anything that would preclude doing so.. 
2: Any suggestions on how a beat-up FT-226-A tray might accommodate either style transmitter? I am thinking having each
rear connector wired for a particular transmitter pin out, but how to avoid accidentally putting the wrong version in the wrong
slot? One side Army, one side Navy...
3: For power... a modified Heathkit PS-23 junker... get rid of the voltage doubler nonsense and use full wave bridges on the
high and low voltage windings. Series the two to provide around 125 vdc for the RX, and around 500 vdc for the TX.
4: Add a half-wave voltage doubler on the 12.6 winding for DC filament voltage for the transmitter filaments and relays.
5 Any benefit to regulating the 200 VDC for the 1626 oscillator? I suspect it would not hurt. 
6: transmitters will be modified following AB5S's suggestions regarding relay adjustments, etc  

Flame away...______________________________________________________________
ARC5 mailing list
Home: http://mailman.qth.net/mailman/listinfo/arc5
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:ARC5 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: https://www.qsl.net/donate.html  
______________________________________________________________
ARC5 mailing list
Home: http://mailman.qth.net/mailman/listinfo/arc5
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:ARC5 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: https://www.qsl.net/donate.html  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20200209/ca0e555f/attachment.html>